1. Field of the Invention
The present invention relates to a technique that evaluates the localized performance of an electronics element that carries out transmission, recording and processing of information, and relates to the industrial field of scanning probe microscopes and micro probe devices for circuit evaluation, etc. and probes etc. thereof.
2. Description of Related Art
In recent years, the expression xe2x80x9cinformation technology (IT) revolutionxe2x80x9d is heard more and more often. This reflects the current situation in which globalization of the information industry supported by a dramatic technological revolution of electronics etc. is becoming a reality. Electronics for sending, receiving, accumulating and processing important amounts of information when needed exist as fundamental technology of the IT revolution, and intensive research and development is being carried out world-wide with the aim of bringing about further technological innovation. In such a situation, the importance of developing techniques to evaluate the abilities of ultra-integrated electronics elements is increasing day after day. For example, with the objective of testing the operation state of memory cells and calculator elements, as a conventional method, operation testing is being carried out in a state where a voltage is applied to the actual circuit by having wires make contact with several micro probers and then detecting current. Alternatively, in non-contact methods, optical methods and such are proposed, in which a circuit is irradiated with a laser, and the electrical current excited by the laser beam is determined. However, concomitant to the recent miniaturization of circuits, with the all the above-mentioned methods, with a line width inside the element in the order of 0.1 xcexcm, ensuring that wires make direct contact with the micro probers is difficult, and narrowing the laser beam to the order of 0.1 xcexcm is extremely difficult.
On another front, for example, Japanese Patent No. 3141555 is proposed as a method that allows detection of electro-magnetic information of microscopic portions in the sub-micron order. This belongs to the so-called scanning probe microscope, and is a magnetic force microscope that detects the electro-magnetic information of a sample surface. Its constitution provides means for mounting a ferromagnetic pointed needle at the tip of a cantilever, means for positioning a magnetic resistant (MR) element at one end of the ferromagnetic pointed needle, means for detecting displacement of the cantilever, means for detecting change in magnetic resistance, means for exciting the cantilever at a specified frequency, means for detecting displacement of the cantilever and the change in magnetic resistance of the specified frequency component, and means for scanning along the sample surface with a probe, and is a scanning magnetic microscope operating on the principle of accurately detecting the position of the sample surface by maintaining the position of the ferromagnetic pointed needle at a constant height above the sample surface from the displacement of the cantilever and determining at the same time the magnetic information from the change in magnetic resistance, and measuring magnetic information by detecting the change in the magnetic resistance above the sample surface at the same location. However, this device has the disadvantages that its sensitivity is insufficient to detect electrical current that flows in the above-mentioned miniaturized wire. In addition, the actual fabrication process of the cantilever such as the accumulation and wiring of MR elements as the detection part becomes cumbersome and complicated. In such a situation, the development of a method is desired which determines the value of the electrical current that actually flows in any portion of the miniaturized integrated circuit, and which furthermore evaluates change in current by breaking the current down spatially and temporally.
Feature of the present invention is to provide a method and device thereof that captures microscopic magnetic signals such as those developed by electrical current flowing inside a circuit that is miniaturized to sub-micron order or less, to evaluate the circuit and provide a probe employed by this method.
The present invention provides a scanning probe microscope constituted by a giant magnetostrictive material, which demonstrates a large magnetostriction characteristic in a weak magnetic field, adhered to a probe portion of a cantilever of the scanning probe microscope, and at the same time as capturing the change in the magnetic flux due to localized change in electrical current, or the magnetic flux of a magnetic body, as a signal of displacement of the giant magnetostrictive material, and on the other hand, detects the local shape of a sample surface with the function of the scanning probe microscope, and dissociates and images the magnetic flux information and shape information from the signal of displacement of the giant magnetostrictive material. Any of the non-crystalline alloys Fe100xe2x88x92xxe2x88x92ySixBy (here, x is a number at the level of 10 and y at the level of 12), Tb1xe2x88x92xDyxFe2 (here, x is a number at the level of 0.73), Fe100xe2x88x92xNi (here, x is between 60 and 40) may be selected as the giant magnetostrictive material.
Further, as a method for forming a probe of magnetostrictive material for use in a scanning probe microscope of the present invention, the end of a probe of a microscopic columnar structure is taken as a base and particles of magnetostrictive material are deposited with directivity using sputtering or electron-deposition methods.